| page.title=Android N for Developers |
| meta.tags="preview", "androidn" |
| page.tags="preview", "developer preview" |
| page.image=images/cards/card-n-apis_2x.png |
| @jd:body |
| |
| |
| |
| |
| <div id="qv-wrapper"> |
| <div id="qv"> |
| <h2>Key developer features</h2> |
| <ol> |
| <ul style="list-style-type:none;"> |
| <li><a href="#multi-window_support">Multi-window support</a></li> |
| <li><a href="#notification_enhancements">Notifications</a></li> |
| <li><a href="#jit_aot">JIT/AOT compilation</a></li> |
| <li><a href="#quick_path_to_app_install">Quick path to app install</a></li> |
| <li><a href="#doze_on_the_go">Doze on the go</a></li> |
| <li><a href="#background_optimizations">Background optimizations</a></li> |
| <li><a href="#data_saver">Data Saver</a></li> |
| <li><a href="#vulkan">Vulkan API</a></li> |
| <li><a href="#tile_api">Quick Settings Tile API</a></li> |
| <li><a href="#number-blocking">Number-blocking</a></li> |
| <li><a href="#call_screening">Call screening</a></li> |
| <li><a href="#multi-locale_languages">Locales and languages</a></li> |
| <li><a href="#emoji">New Emojis</a></li> |
| <li><a href="#icu4">ICU4J APIs in Android</a></li> |
| <li><a href="#gles_32">OpenGL ES 3.2 API</a></li> |
| <li><a href="#android_tv_recording">Android TV recording</a></li> |
| <li><a href="#android_for_work">Android for Work</a></li> |
| <li><a href="#accessibility_enhancements">Accessibility</a></li> |
| <li><a href="#direct_boot">Direct Boot</a></li> |
| <li><a href="#key_attestation">Key Attestation</a></li> |
| <li><a href="#network_security_config">Network Security Config</a></li> |
| <li><a href="#default_trusted_ca">Default Trusted CA</a></li> |
| <li><a href="#apk_signature_v2">APK signature scheme v2</a></li> |
| <li><a href="#scoped_directory_access">Scoped directory access</a></li> |
| <li><a href="#keyboard_shortcuts_helper">Keyboard Shortcuts Helper</a></li> |
| <li><a href="#sustained_performance_api">Sustained Performance API</a></li> |
| <li><a href="#print_svc">Print service enhancements</a></li> |
| <li><a href="#virtual_files">Virtual Files</a></li> |
| <li><a href="#framemetrics_api">FrameMetricsListener API</a></li> |
| </ol> |
| </div> |
| </div> |
| |
| |
| |
| <p>Android N is still in active development, but you can try it |
| now as part of the N Developer Preview. The sections below highlight some of |
| the new features for developers. </p> |
| |
| <p> |
| Make sure to check out the <a href= |
| "{@docRoot}preview/behavior-changes.html">Behavior Changes</a> to learn about |
| areas where platform changes may affect your apps, take a look at the |
| developer guides to learn more about key features, and download the <a href= |
| "{@docRoot}preview/setup-sdk.html#docs-dl">API Reference</a> for details on |
| new APIs. |
| </p> |
| |
| <h2 id="multi-window_support">Multi-window support</h2> |
| |
| |
| <p>In Android N, we're introducing a new and much-requested multitasking feature |
| into the platform — multi-window support. </p> |
| |
| <p>Users can now pop open two apps on the screen at once. </p> |
| <ul> |
| <li>On phones and tablets |
| running Android N, users can run two apps side-by-side or |
| one-above-the-other in splitscreen mode. Users can resize the apps by dragging |
| the divider between them. </li> |
| |
| <li>On Android TV devices, apps can put themselves in <a |
| href="{@docRoot}preview/features/picture-in-picture.html">picture-in-picture |
| mode</a>, allowing them to continue showing content while the user browses or |
| interacts with other apps.</li> |
| </ul> |
| |
| <div class="col-4of10"> |
| <img src="{@docRoot}preview/images/mw-portrait.png" alt="" style="height:460px;padding-left:1em;" |
| id="img-split-screen" /> |
| <p class="img-caption"> |
| <strong>Figure 1.</strong> Apps running in split-screen mode. |
| </p> |
| </div> |
| |
| <p>Especially on tablets and other larger-screen devices, multi-window support |
| gives you new ways to engage users. You can even enable drag-and-drop in |
| your app to let users conveniently drag content to or from your app — a great |
| way to enhance your user experience. </p> |
| |
| <p>It's straightforward to add multi-window support to your app and configure how it |
| handles multi-window display. For example, you can specify your activity's |
| minimum allowable dimensions, preventing users from resizing the activity below |
| that size. You can also disable multi-window display for your app, which |
| ensures that the system will only show your app in full-screen mode.</p> |
| |
| <p> |
| For more information, see the <a href= |
| "{@docRoot}preview/features/multi-window.html">Multi-Window Support</a> |
| developer documentation. |
| </p> |
| |
| <h2 id="notification_enhancements">Notification enhancements</h2> |
| |
| <p>In Android N we've redesigned notifications to make them easier and faster to |
| use. Some of the changes include:</p> |
| |
| <ul> |
| <li> |
| <strong>Template updates</strong>: We're updating notification templates to |
| put a new emphasis on hero image and avatar. Developers will be able to |
| take advantage of the new templates with minimal adjustments in their code. |
| </li> |
| |
| <li> |
| <strong>Message style customization</strong>: You can customize more of the |
| user interface labels associated with your notifications using the |
| <code>MessageStyle</code> class. You can configure the message, conversation |
| title, and content view. |
| </li> |
| |
| <li> |
| <strong>Bundled notifications</strong>: The system can group messages |
| together, for example by message topic, and display the group. A user can |
| take actions, such as Dismiss or Archive, on them in place. If you’ve |
| implemented notifications for Android Wear, you’ll already be familiar with |
| this model. |
| </li> |
| |
| <li> |
| <strong>Direct reply</strong>: For real-time communication apps, the |
| Android system supports inline replies so that users can quickly respond to |
| an SMS or text message directly within the notification interface. |
| </li> |
| |
| <li> |
| <strong>Custom views</strong>: Two new APIs enable you to leverage system |
| decorations, such as notification headers and actions, when using custom |
| views in notifications. |
| </li> |
| </ul> |
| |
| <div class="col-4of12"> |
| <img src="{@docRoot}preview/images/notifications-1.png" alt="" |
| style="padding:.5em;max-width:226px"> |
| </div> |
| |
| <div class="col-4of12"> |
| <img src="{@docRoot}preview/images/notifications-3.png" alt="" |
| style="padding:.5em;max-width:226px"> |
| </div> |
| |
| <div class="col-4of12"> |
| <img src="{@docRoot}preview/images/notifications-2.png" alt="" |
| style="padding:.5em;max-width:226px"> |
| </div> |
| |
| |
| <p class="img-caption"> |
| <strong>Figure 2.</strong> Bundled notifications and direct reply. |
| </p> |
| |
| <p>To learn how to implement the new features, see the |
| <a href="{@docRoot}preview/features/notification-updates.html">Notifications</a> |
| guide.</p> |
| |
| |
| |
| <h2 id="jit_aot">Profile-guided JIT/AOT compilation</h2> |
| |
| <p>In Android N, we've added a Just in Time (JIT) compiler with code profiling to |
| ART, which lets it constantly improve the performance of Android apps as they |
| run. The JIT compiler complements ART's current Ahead of Time (AOT) compiler |
| and helps improve runtime performance, save storage space, and speed up app |
| updates and system updates.</p> |
| |
| <p>Profile-guided compilation lets ART manage the AOT/JIT compilation for each app |
| according to its actual usage, as well as conditions on the device. For |
| example, ART maintains a profile of each app's hot methods and can precompile |
| and cache those methods for best performance. It leaves other parts of the app |
| uncompiled until they are actually used.</p> |
| |
| <p>Besides improving performance for key parts of the app, profile-guided |
| compilation helps reduce an app's overall RAM footprint, including associated |
| binaries. This feature is especially important on low-memory devices.</p> |
| |
| <p>ART manages profile-guided compilation in a way that minimizes impact on the |
| device battery. It does precompilation only when then the device is idle and |
| charging, saving time and battery by doing that work in advance.</p> |
| |
| <h2 id="quick_path_to_app_install">Quick path to app install</h2> |
| |
| <p>One of the most tangible benefits of ART's JIT compiler is the speed of app |
| installs and system updates. Even large apps that required several minutes to |
| optimize and install in Android 6.0 can now install in just a matter of |
| seconds. System updates are also faster, since there's no more optimizing step. </p> |
| |
| <h2 id="doze_on_the_go">Doze on the go...</h2> |
| |
| <p>Android 6.0 introduced Doze, a system mode that saves battery by deferring |
| apps' CPU and network activities when the device is idle, such as when it's |
| sitting on a table or in a drawer. </p> |
| |
| <p>Now in Android N, Doze takes a step further and saves battery while on the go. |
| Any time the screen is off for a period of time and the device is unplugged, |
| Doze applies a subset of the familiar CPU and network restrictions to apps. |
| This means users can save battery even when carrying their devices in their |
| pockets.</p> |
| |
| |
| <img src="/preview/images/doze-diagram-1.png" |
| alt="" id="figure1" /> |
| <p class="img-caption"> |
| <strong>Figure 3.</strong> Doze now applies |
| restrictions to improve battery life even when the device is not stationary. |
| </p> |
| |
| |
| <p>A short time after the screen turns off while the device is on battery, Doze |
| restricts network access and defers jobs and syncs. During brief maintenance |
| windows, applications are allowed network access and any of their deferred |
| jobs/syncs are executed. Turning the screen on or plugging in the device brings |
| the device out of Doze.</p> |
| |
| <p>When the device is stationary again, with screen off and on battery for a |
| period of time, Doze applies the full CPU and network restrictions on {@link |
| android.os.PowerManager.WakeLock}, {@link android.app.AlarmManager} alarms, and |
| GPS/Wi-Fi scans.</p> |
| |
| <p>The best practices for adapting your app to Doze are the same whether the |
| device is moving or not, so if you already updated your app to gracefully |
| handle Doze, you're all set. If not, start <a |
| href="{@docRoot}training/monitoring-device-state/doze-standby.html#assessing_your_app">adapting |
| your app to Doze</a> now.</p> |
| |
| <h2 id="background_optimizations">Project Svelte: Background optimizations</h2> |
| |
| <p>Project Svelte is an ongoing effort to minimize RAM use by system and apps |
| across the range of Android devices in the ecosystem. In Android N, Project |
| Svelte is focused on optimizing the way apps run in the background. </p> |
| |
| <p>Background processing is an essential part of most apps. When handled right, it |
| can make your user experience amazing — immediate, fast, and context-aware. |
| When not handled right, background processing can needlessly consume RAM (and |
| battery) and affect system performance for other apps. </p> |
| |
| <p>Since Android 5.0, {@link android.app.job.JobScheduler} has been the |
| preferred way of performing background work in a way that's good |
| for users. Apps can schedule jobs while letting the system optimize based on |
| memory, power, and connectivity conditions. JobScheduler offers control and |
| simplicity, and we want all apps to use it. </p> |
| |
| <p> |
| Another good option is <a href= |
| "https://developers.google.com/android/reference/com/google/android/gms/gcm/GcmNetworkManager"> |
| <code>GCMNetworkManager</code></a>, part of Google Play Services, which |
| offers similar job scheduling with compatibility across legacy versions of |
| Android. |
| </p> |
| |
| <p>We're continuing to extend <code>JobScheduler</code> and |
| <code>GCMNetworkManager</code> to meet more of |
| your use cases — for example, in Android N you can now schedule background |
| work based on changes in Content Providers. At the same time we're starting to |
| deprecate some of the older patterns that can reduce system performance, |
| especially on low-memory devices.</p> |
| |
| <p>In Android N we're removing three commonly-used implicit broadcasts — |
| {@link android.net.ConnectivityManager#CONNECTIVITY_ACTION}, {@link |
| android.hardware.Camera#ACTION_NEW_PICTURE}, and {@link |
| android.hardware.Camera#ACTION_NEW_VIDEO} — since those can wake the |
| background processes of multiple apps at once and strain memory and battery. If |
| your app is receiving these, take advantage of the N Developer Preview to |
| migrate to <code>JobScheduler</code> and related APIs instead. </p> |
| |
| <p> |
| Take a look at the <a href= |
| "{@docRoot}preview/features/background-optimization.html">Background |
| Optimizations</a> documentation for details. |
| </p> |
| |
| |
| <h2 id="data_saver">Data Saver</h2> |
| |
| <div class="col-5of12" style="margin-right:1.5em;"> |
| <img src="{@docRoot}preview/images/datasaver.png" style="border:2px solid #ddd"> |
| |
| <p class="img-caption" style="padding-right:2em;"> |
| <strong>Figure 4.</strong> Data Saver in Settings. |
| </p> |
| </div> |
| |
| <p>Over the life of a mobile device, the cost of a cellular data plan typically |
| exceeds the cost of the device itself. For many users, cellular data is an |
| expensive resource that they want to conserve. </p> |
| |
| <p>Android N introduces Data Saver mode, a new system service that helps reduce |
| cellular data use by apps, whether roaming, near the end of the billing cycle, |
| or on a small prepaid data pack. Data Saver gives users control over how apps |
| use cellular data and lets developers provide more efficient service when Data |
| Saver is on. </p> |
| |
| <p>When a user enables Data Saver in <strong>Settings</strong> and the device is |
| on a metered network, the system blocks background data usage and signals apps |
| to use less data in the foreground wherever possible — such as by limiting |
| bit rate for streaming, reducing image quality, deferring optimistic precaching, |
| and so on. Users can whitelist specific apps to allow background metered data |
| usage even when Data Saver is turned on.</p> |
| |
| <p>Android N extends the {@link android.net.ConnectivityManager} to provide apps a |
| way to <a href="{@docRoot}preview/features/data-saver.html#status">retrieve the |
| user's Data Saver preferences</a> and <a |
| href="{@docRoot}preview/features/data-saver.html#monitor-changes">monitor |
| preference changes</a>. All apps should check whether the user has enabled Data |
| Saver and make an effort to limit foreground and background data usage.</p> |
| |
| |
| <h2 id="vulkan">Vulkan API</h2> |
| |
| <p> |
| Android N integrates <a href="http://www.khronos.org/vulkan" class= |
| "external-link">Vulkan™</a>, a new 3D rendering API, into the platform. Like |
| <a href="https://www.khronos.org/opengles/" class="external-link">OpenGL™ |
| ES</a>, Vulkan is an open standard for 3D graphics and rendering maintained |
| by the Khronos Group. |
| </p> |
| |
| <p> |
| Vulkan is designed from the ground up to minimize CPU overhead in the driver, |
| and allow your application to control GPU operation more directly. Vulkan |
| also enables better parallelization by allowing multiple threads to perform |
| work such as command buffer construction at once. |
| </p> |
| |
| <p> |
| Vulkan development tools and libraries are rolled into the Android NDK. They |
| include: |
| </p> |
| |
| <ul> |
| <li>Headers |
| </li> |
| |
| <li>Validation layers (debug libraries) |
| </li> |
| |
| <li>SPIR-V shader compiler |
| </li> |
| |
| <li>SPIR-V runtime shader compilation library |
| </li> |
| </ul> |
| |
| <p> |
| Vulkan is only available to apps on devices with Vulkan-capable hardware, |
| such as Nexus 5X, Nexus 6P, and Nexus Player. We're working closely with our |
| partners to bring Vulkan to more devices as soon as possible. |
| </p> |
| |
| <p> |
| For more information, see the the <a href= |
| "{@docRoot}ndk/guides/graphics/index.html">API documentation</a>. |
| </p> |
| |
| <h2 id="tile_api">Quick Settings Tile API</h2> |
| |
| |
| <div style="float:right;max-width:320px"> |
| <img src="{@docRoot}preview/images/quicksettings.png" style="padding-left:1.5em;"> |
| |
| <p class="img-caption" style="padding-left:2em;"> |
| <strong>Figure 5.</strong> Quick Settings tiles in the notification shade. |
| </p> |
| |
| |
| </div><p>Quick Settings is a popular and simple way to expose key settings and actions, |
| directly from the notification shade. In Android N, we've expanded the scope of |
| Quick Settings to make it even more useful and convenient. </p> |
| |
| <p>We've added more room for additional Quick Settings tiles, which users can |
| access across a paginated display area by swiping left or right. We've also |
| given users control over what Quick Settings tiles appear and where they are |
| displayed — users can add or move tiles just by dragging and dropping them. </p> |
| |
| <p>For developers, Android N also adds a new API that lets you define your own |
| Quick Settings tiles to give users easy access to key controls and actions in your app.</p> |
| |
| <p> |
| Quick Settings tiles are reserved for controls or actions that are either |
| urgently required or frequently used, and should not be used as shortcuts to |
| launching an app. |
| </p> |
| |
| <p> |
| Once you’ve defined your tiles, you can surface them to users, who can add |
| them to Quick Settings just by drag and drop. |
| </p> |
| |
| <p> |
| For information about creating an app tile, see the |
| <code>android.service.quicksettings.Tile</code> in the downloadable <a href= |
| "{@docRoot}preview/setup-sdk.html#docs-dl">API Reference</a>. |
| </p> |
| |
| |
| |
| <h2 id="number-blocking">Number-blocking</h2> |
| |
| <p>Android N now supports number-blocking in the platform and provides a |
| framework API to let service providers maintain a blocked-number list. The |
| default SMS app, the default phone app, and carrier apps can read from and |
| write to the blocked-number list. The list is not accessible to other apps.</p> |
| |
| <p>By making number-blocking a standard feature of the platform, Android provides |
| a consistent way for apps to support number-blocking across a wide range of |
| devices. Among the other benefits that apps can take advantage of are:</p> |
| |
| <ul> |
| <li> Numbers blocked on calls are also blocked on texts |
| <li> Blocked numbers can persist across resets and devices through the Backup & |
| Restore feature |
| <li> Multiple apps can use the same blocked numbers list |
| </ul> |
| |
| <p>Additionally, carrier app integration through Android means that carriers can |
| read the blocked numbers list on the device and perform service-side blocking |
| for the user in order to stop unwanted calls and texts from reaching the user |
| through any medium, such as a VOIP endpoint or forwarding phones.</p> |
| |
| <p> |
| For more information, see <code>android.provider.BlockedNumberContract</code> |
| in the downloadable <a href="{@docRoot}preview/setup-sdk.html#docs-dl">API |
| Reference</a>. |
| </p> |
| |
| <h2 id="call_screening">Call screening</h2> |
| |
| <p> |
| Android N allows the default phone app to screen incoming calls. The phone |
| app does this by implementing the new <code>CallScreeningService</code>, |
| which allows the phone app to perform a number of actions based on an |
| incoming call's {@link android.telecom.Call.Details Call.Details}, such as: |
| </p> |
| |
| <ul> |
| <li> Reject the incoming call |
| <li> Do not allow the call to the call log |
| <li> Do not show the user a notification for the call |
| </ul> |
| |
| <p> |
| For more information, see <code>android.telecom.CallScreeningService</code> |
| in the downloadable <a href="{@docRoot}preview/setup-sdk.html#docs-dl">API |
| Reference</a>. |
| </p> |
| |
| |
| <h2 id="multi-locale_languages">Multi-locale support, more languages</h2> |
| |
| |
| <p>Android N now lets users select <strong>multiple locales</strong> in Settings, |
| to better support bilingual use-cases. Apps can use |
| a new API to get the user's selected locales and then offer more sophisticated |
| user experiences for multi-locale users — such as showing search results in |
| multiple languages and not offering to translate webpages in a language the |
| user already knows.</p> |
| |
| <p>Along with multi-locale support, Android N also expands the range of languages |
| available to users. It offers more than 25 variants each for commonly used |
| languages such as English, Spanish, French, and Arabic. It also adds partial |
| support for more than 100 new languages.</p> |
| |
| <p>Apps can get the list of locales set by the user by calling <code>LocaleList.GetDefault()</code>. To support the expanded number of locales, Android N is changing the way |
| that it resolves resources. Make sure that you test and verify that your apps |
| working as expected with the new resource resolution logic.</p> |
| |
| <p>To learn about the new resource-resolution behavior and the best practices you |
| should follow, see <a href="{@docRoot}preview/features/multilingual-support.html" |
| >Multilingual Support</a>.</p> |
| |
| |
| <h2 id="emoji">New Emojis</h2> |
| |
| <p> |
| Android N introduces additional emojis and emoji-related features including |
| skin tone emojis and support for variation |
| selectors. If your app supports emojis, |
| follow the guidelines below to take advantage of these emoji-related features. |
| </p> |
| |
| <ul> |
| <li> |
| <strong>Check that a device contains an emoji before inserting it.</strong> |
| To check which emojis are present in the |
| system font, use the {@link android.graphics.Paint#hasGlyph(String)} method. |
| </li> |
| <li> |
| <strong>Check that an emoji supports variation selectors.</strong> |
| Variation selectors allow you to |
| present certain emojis in color or in black-and-white. |
| On mobile devices, apps should represent emojis in color rather than black-and-white. However, |
| if your app displays emojis inline with text, then it should use the black-and-white variation. |
| To determine whether an emoji has a variation, use the variation selector. |
| For a complete list of characters with variations, review the |
| <em>emoji variation sequences</em> section of the |
| <a class="external-link" |
| href="http://www.unicode.org/Public/9.0.0/ucd/StandardizedVariants-9.0.0d1.txt"> |
| Unicode documentation on variations</a>. |
| </li> |
| <li> |
| <strong>Check that an emoji supports skin tone.</strong> Android N allows users to modify the |
| rendered skin tone of emojis to their preference. Keyboard apps should provide visual |
| indications for emojis that have multiple skin tones and should allow users to |
| select the skin tone that they prefer. To determine which system emojis have |
| skin tone modifiers, use the {@link android.graphics.Paint#hasGlyph(String)} |
| method. You can determine which emojis use skin tones by reading the |
| <a class="external-link" |
| href="http://unicode.org/emoji/charts/full-emoji-list.html"> |
| Unicode documentation</a>. |
| </li> |
| </ul> |
| |
| |
| <h2 id="icu4">ICU4J APIs in Android</h2> |
| |
| <p> |
| Android N now offers a subset of <a href= |
| "http://site.icu-project.org/">ICU4J</a> APIs in the Android framework under |
| the <code>android.icu</code> package. Migration is easy, and mostly entails |
| simply changing from the <code>com.java.icu</code> namespace to |
| <code>android.icu</code>. If you are already using an ICU4J bundle in your |
| apps, switching to the <code>android.icu</code> APIs provided in the Android |
| framework can produce substantial savings in APK size. |
| </p> |
| |
| <p> |
| To learn more about the Android ICU4J APIs, see <a href= |
| "{@docRoot}preview/features/icu4j-framework.html">ICU4J Support</a>. |
| </p> |
| |
| |
| |
| <h2 id="gles_32">OpenGL™ ES 3.2 API</h2> |
| |
| <p>Android N adds framework interfaces and platform support for OpenGL ES 3.2, including:</p> |
| |
| <ul> |
| <li> All extensions from the <a class="external-link" |
| href="https://www.khronos.org/registry/gles/extensions/ANDROID/ANDROID_extension_pack_es31a.txt">Android Extension Pack</a></a> (AEP) except for <code>EXT_texture_sRGB_decode</code>. |
| <li> Floating-point framebuffers for HDR and deferred shading. |
| <li> BaseVertex draw calls to enable better batching and streaming. |
| <li> Robust buffer access control to reduce WebGL overhead. |
| </ul> |
| |
| <p>The framework API for OpenGL ES 3.2 on Android N is provided with the |
| <code>GLES32</code> class. When using OpenGL ES 3.2, be sure to declare the |
| requirement in your manifest file, using the <code><uses-feature></code> tag and |
| the <code>android:glEsVersion</code> attribute. </p> |
| |
| <p>For information about using OpenGL ES, including how to check a device's |
| supported OpenGL ES version at runtime, see the <a |
| href="{@docRoot}guide/topics/graphics/opengl.html">OpenGL ES API guide</a>.</p> |
| |
| |
| <h2 id="android_tv_recording">Android TV recording</h2> |
| |
| <p>Android N adds the ability to record and playback content from Android TV input |
| services via new recording APIs. Building on top of existing time-shifting |
| APIs, TV input services can control what channel data can be recorded, how |
| recorded sessions are saved, and manage user interaction with recorded content. </p> |
| |
| <p>For more information, see <a |
| href="{@docRoot}preview/features/tv-recording-api.html">Android TV Recording APIs</a>.</p> |
| |
| |
| <h2 id="android_for_work">Android for Work</h2> |
| |
| <p>Android for Work adds many new features and APIs for devices running Android N. |
| Some highlights are below — for a complete list of changes, see |
| <a href="{@docRoot}preview/features/afw.html">Android for Work Updates</a>.</p> |
| |
| <h3 id="work_profile_security_challenge">Work profile security challenge </h3> |
| |
| <p> |
| Profile owners targeting the N SDK |
| can specify a separate security challenge for apps running in |
| the work profile. The work challenge is shown when a user attempts to open |
| any work apps. Successful completion of the security challenge unlocks the |
| work profile and decrypts it if necessary. For profile owners, |
| <code>ACTION_SET_NEW_PASSWORD</code> prompts the user to set a work |
| challenge, and <code>ACTION_SET_NEW_PARENT_PROFILE_PASSWORD</code> prompts |
| the user to set a device lock. |
| </p> |
| |
| <p> |
| Profile owners can set distinct passcode policies for the work challenge |
| (such as how long the PIN needs to be, or whether a fingerprint can be used |
| to unlock the profile) using the <code>setPasswordQuality()</code>, |
| <code>setPasswordMinimumLength()</code> and related methods. The profile |
| owner can also set the device lock using the <code>DevicePolicyManager</code> |
| instance returned by the new <code>getParentProfileInstance()</code> method. |
| Additionally, profile owners can customize the credentials screen for the |
| work challenge using the new <code>setOrganizationColor()</code> and |
| <code>setOrganizationName()</code> methods. |
| </p> |
| <h3 id="turn_off_work">Turn off work </h3> |
| |
| <p>On a device with a work profile, users can toggle work mode. When work mode is |
| off the managed user is temporarily shut down, which disables work profile |
| apps, background sync, and notifications. This includes the profile owner |
| application. When work mode is off, the system displays a persistent status |
| icon to remind the user that they can't launch work apps. The launcher |
| indicates that work apps and widgets are not accessible. </p> |
| |
| <h3 id="always_on_vpn">Always on VPN </h3> |
| |
| <p>Device owners and profile owners can ensure that work apps always connect |
| through a specified VPN. The system automatically starts that VPN after the |
| device boots.</p> |
| |
| <p> |
| New <code>DevicePolicyManager</code> methods are |
| <code>setAlwaysOnVpnPackage()</code> and |
| <code>getAlwaysOnVpnPackage()</code>. |
| </p> |
| |
| <p>Because VPN services can be bound directly by the system without app |
| interaction, VPN clients need to handle new entry points for Always on VPN. As |
| before, services are indicated to the system by an intent filter matching |
| action <code>android.net.VpnService</code>. </p> |
| |
| <p> |
| Users can also manually set Always on VPN clients that implement |
| <code>VPNService</code> methods in the primary user using |
| <strong>Settings>More>Vpn</strong>. |
| </p> |
| |
| <h3 id="custom_provisioning">Customized provisioning</h3> |
| |
| <p> |
| An application can customize the profile owner and device owner provisioning |
| flows with corporate colors and logos. |
| <code>DevicePolicyManager.EXTRA_PROVISIONING_MAIN_COLOR</code> customizes |
| flow color. <code>DevicePolicyManager.EXTRA_PROVISIONING_LOGO_URI</code> |
| customizes the flow with a corporate logo. |
| </p> |
| |
| <h2 id="accessibility_enhancements">Accessibility enhancements</h2> |
| |
| <p>Android N now offers Vision Settings directly on the Welcome screen for new |
| device setup. This makes it much easier for users to discover and configure |
| accessibility features on their devices, including magnification gesture, font |
| size, display size, and TalkBack. </p> |
| |
| <p>With these accessibility features getting more prominent placement, your users |
| are more likely to try your app with them enabled. Make sure you test your apps |
| early with these settings enabled. You can enable them from Settings > |
| Accessibility.</p> |
| |
| <p>Also in Android N, accessibility services can now help users with motor |
| impairments to touch the screen. The new API allows building services with |
| features such as face-tracking, eye-tracking, point scanning, and so on, to |
| meet the needs of those users.</p> |
| |
| <p>For more information, see <code>android.accessibilityservice.GestureDescription</code> |
| in the downloadable <a href="{@docRoot}preview/setup-sdk.html#docs-dl">API Reference</a>.</p> |
| |
| |
| <h2 id="direct_boot">Direct boot</h2> |
| |
| <p>Direct boot improves device startup times and lets registered |
| apps have limited functionality even after an unexpected reboot. |
| For example, if an encrypted device reboots while the user is sleeping, |
| registered alarms, messages and incoming calls can now continue to notify |
| the user as normal. This also means accessibility services can also be |
| available immediately after a restart.</p> |
| |
| <p>Direct boot takes advantage of file based encryption in Android N |
| to enable fine grained encryption policies for both system and app data. |
| The system uses a device-encrypted store for select system data and explicitly |
| registered app data. By default a credential-encrypted store is used for all |
| other system data, user data, apps, and app data. </p> |
| |
| <p>At boot, the system starts in a restricted mode with access to |
| device-encrypted data only, and without general access to apps or data. |
| If you have components that you want to run in this mode, you can register |
| them by setting a flag in the manifest. After restart, the system activates |
| registered components by broadcasting the <code>LOCKED_BOOT_COMPLETED</code> |
| intent. The system ensures registered device-encrypted app data is available |
| before unlock. All other data is unavailable until the User confirms their lock |
| screen credentials to decrypt it. </p> |
| |
| For more information, see <a href="{@docRoot}preview/features/direct-boot.html">Direct Boot</a>.</p> |
| </p> |
| |
| |
| <h2 id="key_attestation">Key Attestation</h2> |
| |
| <p>Hardware-backed keystores provide a much safer method to create, store, |
| and use cryptographic keys on Android devices. They protect keys from the |
| Linux kernel, potential Android vulnerabilities, and extraction |
| from rooted devices.</p> |
| |
| <p>To make it easier and more secure to use hardware-backed keystores, |
| Android N introduces Key Attestation. Apps and off-devices can use Key |
| Attestation to strongly determine whether an RSA or EC key pair is |
| hardware-backed, what the properties of the key pair are, and what |
| constraints are applied to its usage and validity. </p> |
| |
| <p>Apps and off-device services can request information about a key pair |
| through an X.509 attestation certificate which must be signed by a valid |
| attestation key. The attestation key is an ECDSA signing key which is |
| injected into the device’s hardware-backed keystore at the factory. |
| Therefore, an attestation certificate signed by a valid attestation |
| key confirms the existence of a hardware-backed keystore, along with |
| details of key pairs in that keystore.</p> |
| |
| <p>To ensure that the device is using a secure, official Android factory |
| image, Key Attestation requires that the device <a |
| class="external-link" |
| href="https://source.android.com/security/verifiedboot/verified-boot.html#bootloader_requirements">bootloader</a> |
| provide the following information to the <a class="external-link" |
| href="https://source.android.com/security/trusty/index.html">Trusted |
| Execution Environment (TEE)</a>:</p> |
| |
| <ul> |
| <li>The OS version and patch level installed on the device</li> |
| <li>The <a href="https://source.android.com/security/verifiedboot/index.html" |
| class="external-link" >Verified Boot</a> public key and lock status</li> |
| </ul> |
| |
| <p>For more information about the hardware-backed keystore feature, |
| see the guide for <a href="https://source.android.com/security/keystore/" |
| class="external-link">Hardware-backed Keystore</a>.</p> |
| |
| <p>In addition to Key Attestation, Android N also introduces |
| fingerprint-bound keys that are not revoked on fingerprint enrollment.</p> |
| |
| <h2 id="network_security_config">Network Security Config</h2> |
| |
| <p>In Android N, apps can customize the behavior of their secure (HTTPS, TLS) |
| connections safely, without any code modification, by using the declarative |
| <em>Network Security Config</em> instead of using the conventional |
| error-prone programmatic APIs (e.g. X509TrustManager).</p> |
| |
| <p>Supported features:</p> |
| <ul> |
| <li><b>Custom trust anchors.</b> Lets an application customize which |
| Certificate Authorities (CA) are trusted for its secure connections. For |
| example, trusting particular self-signed certificates or a restricted set of public CAs. |
| </li> |
| <li><b>Debug-only overrides.</b> Lets an application developer safely debug |
| secure connections of their application without added risk to the installed |
| base. |
| </li> |
| <li><b>Cleartext traffic opt-out.</b> Lets an application protect itself from |
| accidental usage of cleartext traffic.</li> |
| <li><b>Certificate pinning.</b> An advanced feature that lets an application |
| limit which server keys are trusted for secure connections.</li> |
| </ul> |
| |
| <p>For more information, see <a |
| href="{@docRoot}preview/features/security-config.html">Network Security |
| Config</a>.</p> |
| |
| <h2 id="default_trusted_ca">Default Trusted Certificate Authority</h2> |
| |
| <p>By default, apps that target Android N only trust system-provided certificates |
| and no longer trust user-added Certificate Authorities (CA). Apps targeting Android |
| N that wish to trust user-added CAs should use the |
| <a href="{@docRoot}preview/features/security-config.html">Network Security Config</a> to |
| specify how user CAs should be trusted.</p> |
| |
| <h2 id="apk_signature_v2">APK signature scheme v2</h2> |
| |
| <p> |
| Android N introduces APK Signature Scheme v2, a new app-signing scheme that |
| offers faster app install times and more protection against unauthorized |
| alterations to APK files. By default, Android Studio 2.2 and the Android |
| Plugin for Gradle 2.2 sign your app using both APK Signature Scheme v2 and |
| the traditional signing scheme, which uses JAR signing. |
| </p> |
| |
| <p> |
| Although we recommend applying APK Signature Scheme v2 to your app, this new |
| scheme is not mandatory. If your app doesn't build properly when using APK |
| Signature Scheme v2, you can disable the new scheme. The disabling process |
| causes Android Studio 2.2 and the Android Plugin for Gradle 2.2 to sign your |
| app using only the traditional signing scheme. To sign with only the |
| traditional scheme, open the module-level <code>build.gradle</code> file, then |
| add the line <code>v2SigningEnabled false</code> to your release signing |
| configuration: |
| </p> |
| |
| <pre> |
| android { |
| ... |
| defaultConfig { ... } |
| signingConfigs { |
| release { |
| storeFile file("myreleasekey.keystore") |
| storePassword "password" |
| keyAlias "MyReleaseKey" |
| keyPassword "password" |
| <strong>v2SigningEnabled false</strong> |
| } |
| } |
| } |
| </pre> |
| |
| <p class="caution"><strong>Caution: </strong> If you sign your app using APK |
| Signature Scheme v2 and make further changes to the app, the app's signature |
| is invalidated. For this reason, use tools such as <code>zipalign</code> |
| before signing your app using APK Signature Scheme v2, not after. |
| </p> |
| |
| <p> |
| For more information, read the Android Studio documents that describe how to |
| <a href="{@docRoot}studio/tools/publishing/app-signing.html#release-mode"> |
| sign an app</a> in Android Studio and how to <a href= |
| "{@docRoot}studio/tools/building/configuring-gradle.html#signing"> configure |
| the build file for signing apps</a> using the Android Plugin for Gradle. |
| </p> |
| |
| <h2 id="scoped_directory_access">Scoped directory access</h2> |
| |
| <p>In Android N, apps can use new APIs to request access to specific <a |
| href="{@docRoot}guide/topics/data/data-storage.html#filesExternal">external |
| storage</a> directories, including directories on removable media such as SD |
| cards. The new APIs greatly simplify how your application accesses standard |
| external storage directories, such as the <code>Pictures</code> directory. Apps |
| like photo apps can use these APIs instead of using |
| <code>READ_EXTERNAL_STORAGE</code>, which grants access to all storage |
| directories, or the Storage Access Framework, which makes the user navigate to |
| the directory.</p> |
| |
| <p>Additionally, the new APIs simplify the steps a user takes to grant external |
| storage access to your app. When you use the new APIs, the system uses a simple |
| permissions UI that clearly details what directory the application is |
| requesting access to.</p> |
| |
| <p>For more information, see the |
| <a href="{@docRoot}preview/features/scoped-folder-access.html">Scoped |
| Directory Access</a> developer documentation.</p> |
| |
| <h2 id="keyboard_shortcuts_helper">Keyboard Shortcuts Helper</h2> |
| |
| <p> |
| In Android N, the user can press Meta+/ to trigger a Keyboard Shortcuts |
| screen that displays all shortcuts available both from the system and from |
| the app in focus. These are retrieved automatically from the app’s menu if |
| available, but developers can provide their own fine-tuned shortcuts lists |
| for the screen. This is done simply by overriding the following method |
| in {@code Activity.java}: |
| </p> |
| |
| <pre> |
| public void onProvideKeyboardShortcuts( |
| List<KeyboardShortcutGroup> data, Menu menu, int deviceId) |
| </pre> |
| |
| <p> |
| To trigger the Keyboard Shortcuts Helper from anywhere in your app, |
| call {@code requestKeyboardShortcutsHelper} for the relevant activity. |
| </p> |
| |
| <h2 id="sustained_performance_api">Sustained Performance API</h2> |
| |
| <p> |
| Performance can fluctuate dramatically for long-running apps, because the |
| system throttles system-on-chip engines as device components reach their |
| temperature limits. This fluctuation presents a moving target for app |
| developers creating high-performance, long-running apps. |
| </p> |
| |
| <p> |
| To address these limitations, Android N includes support for |
| <em>sustained performance mode</em>, enabling OEMs to provide hints on |
| device-performance capabilities for long-running applications. App developers |
| can use these hints to tune applications for a predictable, |
| consistent level of device performance over long periods of time. |
| </p> |
| |
| <p> |
| App developers can try out this new API in the N Developer Preview on |
| Nexus 6P devices only. To use this feature, |
| set the sustained performance window flag for the window |
| you want to run in sustained performance mode. Set this flag using the |
| {@code setSustainedPerformanceMode(boolean)} method. The system automatically |
| disables this mode when the window is no longer in focus. |
| </p> |
| |
| <h2 id="print_svc">Print Service Enhancements</h2> |
| |
| <p> |
| In Android N, print service developers can now surface additional information |
| about individual printers and print jobs. |
| </p> |
| |
| <p> |
| When listing individual printers, a print service can now set per-printer |
| icons in two ways: |
| </p> |
| |
| <ul> |
| <li>You can set an icon from a resource ID by calling |
| <code>PrinterInfo.Builder.setResourceIconId()</code> |
| </li> |
| |
| <li>You can show an icon from the network by calling |
| <code>PrinterInfo.Builder.setHasCustomPrinterIcon()</code>, and setting a |
| callback for when the icon is requested using |
| <code>android.printservice.PrinterDiscoverySession.onRequestCustomPrinterIcon()</code> |
| </li> |
| </ul> |
| |
| <p> |
| In addition, you can provide a per-printer activity to display additional |
| information by calling <code>PrinterInfo.Builder.setInfoIntent()</code>. |
| </p> |
| |
| <p> |
| You can indicate the progress and status of print jobs in the print job |
| notification by calling |
| <code>android.printservice.PrintJob.setProgress()</code> and |
| <code>android.printservice.PrintJob.setStatus()</code>, respectively. |
| </p> |
| |
| <p> |
| For more information about these methods, see the downloadable <a href= |
| "{@docRoot}preview/setup-sdk.html#docs-dl">API Reference</a>. |
| </p> |
| |
| <h2 id="framemetrics_api">FrameMetricsListener API</h2> |
| |
| <p> |
| The FrameMetricsListener API allows an app to monitor its UI rendering |
| performance by exposing a streaming pubsub API to transfer frame |
| timing info for the app's current window. The data returned is |
| equivalent to that displayed by {@code adb shell dumpsys gfxinfo framestats}, |
| but is not limited to the past 120 frames. |
| </p> |
| |
| <p> |
| You can use FrameMetricsListener to measure interaction-level UI |
| performance in production, without a USB connection. This API |
| allows collection of data at a much higher granularity than does |
| {@code adb shell dumpsys gfxinfo}. This higher granularity is possible because |
| the system can collect data for particular interactions in the app; the system |
| need not capture a global summary of the entire app’s |
| performance, or clear any global state. You can use this |
| capability to gather performance data and catch regressions in UI performance |
| for real use cases within an app. |
| </p> |
| |
| <p> |
| The API provides a callback interface to be implemented and |
| registered on the window that you wish to monitor: |
| </p> |
| |
| <pre> |
| public interface FrameMetricsListener { |
| void onMetricsAvailable(Window window, FrameMetrics frameMetrics, |
| int dropCountSinceLastInvocation); |
| } |
| </pre> |
| |
| <p> |
| The API returns a FrameMetrics object, which contains timing data that |
| the rendering subsystem reports for various milestones in a frame lifecycle. |
| The supported metrics are: {@code UNKNOWN_DELAY_DURATION}, |
| {@code INPUT_HANDLING_DURATION}, {@code ANIMATION_DURATION}, |
| {@code LAYOUT_MEASURE_DURATION}, {@code DRAW_DURATION}, {@code SYNC_DURATION}, |
| {@code COMMAND_ISSUE_DURATION}, {@code SWAP_BUFFERS_DURATION}, |
| {@code TOTAL_DURATION}, and {@code FIRST_DRAW_FRAME} |
| </p> |
| |
| |
| <h2 id="virtual_files">Virtual Files</h2> |
| |
| <p> |
| In previous versions of Android, your app could use the Storage Access |
| Framework to allow users to select files from their cloud storage accounts, |
| such as Google Drive. However, there was no way to represent files that did |
| not have a direct bytecode representation; every file was required to provide |
| an input stream. |
| </p> |
| |
| <p> |
| Android N adds the concept of <em>virtual files</em> to the Storage Access |
| Framework. The virtual files feature allows your |
| {@link android.provider.DocumentsProvider} to return document URIs that can be |
| used with an {@link android.content.Intent#ACTION_VIEW} intent even if they |
| don't have a direct bytecode representation. Android N also allows you to |
| provide alternate formats for user files, virtual or otherwise. |
| </p> |
| |
| <p> |
| To get a URI for a virtual document in your app, first you create an |
| {@link android.content.Intent} to open the file picker UI. Since an app |
| cannot directly open a virtual file by using the |
| {@link android.content.ContentResolver#openInputStream(Uri) openInputStream()} |
| method, your app does not receive any virtual files if you include the |
| {@link android.content.Intent#CATEGORY_OPENABLE} category. |
| </p> |
| |
| <p> |
| After the user has made a selection, the system calls the |
| {@link android.app.Activity#onActivityResult onActivityResult()} method. |
| Your app can retrieve the URI of the virtual file and get an input stream, as |
| demonstrated in the code snippet below. |
| </p> |
| |
| <pre> |
| // Other Activity code ... |
| |
| final static private int REQUEST_CODE = 64; |
| |
| // We listen to the OnActivityResult event to respond to the user's selection. |
| @Override |
| public void onActivityResult(int requestCode, int resultCode, |
| Intent resultData) { |
| try { |
| if (requestCode == REQUEST_CODE && |
| resultCode == Activity.RESULT_OK) { |
| |
| Uri uri = null; |
| |
| if (resultData != null) { |
| uri = resultData.getData(); |
| |
| ContentResolver resolver = getContentResolver(); |
| |
| // Before attempting to coerce a file into a MIME type, |
| // check to see what alternative MIME types are available to |
| // coerce this file into. |
| String[] streamTypes = |
| resolver.getStreamTypes(uri, "*/*"); |
| |
| AssetFileDescriptor descriptor = |
| resolver.openTypedAssetFileDescriptor( |
| uri, |
| streamTypes[0], |
| null); |
| |
| // Retrieve a stream to the virtual file. |
| InputStream inputStream = descriptor.createInputStream(); |
| } |
| } |
| } catch (Exception ex) { |
| Log.e("EXCEPTION", "ERROR: ", ex); |
| } |
| } |
| </pre> |
| |
| <p> |
| For more information about accessing user files, see the |
| <a href="{@docRoot}guide/topics/providers/document-provider.html">Storage |
| Access Frameworks guide</a>. |
| </p> |